I recently bought a 1997 Isuzu Rodeo 4x4 automatic transmission. It didn't have the owners manual and the previous owner had no idea. What does the "power" button do? I assume it has something to do with traction or towing?

 

it makes the transmission shift at higher RPMs for a more powerful feel

 

It adjusts the shift pattern to keep it in a lower gear in a high duration. It is used majorly for pulling a trailer on hills.